[arm-allstar] simpleusb / channel driver merge status?

Mon Oct 2 11:19:05 EST 2017

Hey Stanley,

I hope I don't sound too defensive; I'm a bit stressed about the whole
thing and I have a lot of work that I know needs to be done, I want to
get it done, and I haven't had time to do it =]

Can you tell me where to find or find information on a harmonic
filter? I understand the concept but don't know where I'd find such a
thing =]

Richard

On Mon, Oct 2, 2017 at 9:30 AM, Stanley Stanukinos <ka5iid at swbell.net> wrote:
> Richard, a band pass filter (can) is not a second harmonic filter. The second harmonic filter is normally in line right after the isolator. It is a small device.
>
> The intermod study depending upon the number of frequencies involved simple or complex. There are programs out that will do the task. Some are free some cost money.
>
> If am am coming off sounding condescending, sorry. I am not intending to. I am just trying to get the point across.  You could also have a TX a couple of miles away get into the mix and cause issues.
>
> You and your teams head will be hurting for a while as you research this problem
>
> Stan
>
> Sent from my iPhone
>
>> On Oct 2, 2017, at 10:07 AM, Richard Bateman <richard at batemansr.us> wrote:
>>
>> Hi Stanley, Doug,
>>
>> I do have an isolator on the transmitter, as well as an extra bandpass
>> filter on both the TX and RX. I haven't tried adding a wattmeter
>> inline for testing -- that's not a bad idea.
>>
>> I don't know how to do a "full intermod study" but have a colleague
>> who has been helping as he can who has started doing some of that; we
>> have a lot of work to do on the mountain, but just haven't had time to
>> do it all.  As I've stated several times, I'm mostly trying to
>> eliminate simple things that I can do remotely at the moment since I
>> have limited time over the next couple of weeks and I don't know when
>> the weather is going to turn.
>>
>> Richard
>>
>> On Mon, Oct 2, 2017 at 8:44 AM, "Stanley Stanukinos via arm-allstar"
>> <arm-allstar at hamvoip.org> wrote:
>>> Richard, you stated you have an isolator on the transmitter. Do you have a second harmonic filter after the isolator? Also have you done a full intermod study on the site including the if frequencies? That may answer some questions.
>>>
>>> Stan
>>>
>>> Sent from my iPhone
>>>
>>>> On Oct 2, 2017, at 9:38 AM, Doug Crompton via arm-allstar <arm-allstar at hamvoip.org> wrote:
>>>>
>>>> While they are expensive repeaters in high RF areas should use an isolator
>>>> (circulator) on the TX line to the duplexor. This not only reduces external
>>>> RF from entering the the transmitter and producing possible intermod
>>>> products but also protects the transmitter from a high SWR should something
>>>> happen to the antenna. Many commercial towers require their use. Stick a
>>>> watt meter on the antenna and you often see watts of out of band power
>>>> coming down from the antenna in a high RF area.
>>>>
>>>>
>>>> *73 Doug*
>>>>
>>>> *WA3DSP*
>>>>
>>>> *http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*
>>>>
>>>>
>>>>
>>>> On Mon, Oct 2, 2017 at 10:25 AM, "Richard Bateman via arm-allstar" <
>>>> arm-allstar at hamvoip.org> wrote:
>>>>
>>>>> Hi David,
>>>>>
>>>>> Yeah, I'm actually getting both of those issues =] I don't think the
>>>>> echo issue is actually related to desense in this case, though, I
>>>>> think we have a mixing product somewhere.  I've got an extra bandpass
>>>>> cavities on both sides and I've done some tests and the sensitivity of
>>>>> the receiver does not seem to be meaningfully impacted when the
>>>>> repeater is transmitting.
>>>>>
>>>>> The random keying issue could well be something like you suggest;
>>>>> oddly, only that repeater of the 4 on the same tower is affected and
>>>>> while I am using some LMR400 on the tower still, it's all very new
>>>>> (temporary while we make sure our antenna setup is where it will be)
>>>>> and this antenna is actually the one that *is* using heliax.  I've
>>>>> also got an isolator on this one, but there isn't on most of the other
>>>>> ones. If the issue happened all the time it'd be a lot easier to track
>>>>> down, of course =]
>>>>>
>>>>> That does remind me, though, that I don't think I've put the antenna
>>>>> analyzer on the full antenna system -- I know the antenna itself was
>>>>> very very good (something like 1.15:1) when I put it up, but I haven't
>>>>> tested it through the feedline or through the duplexer and I should do
>>>>> that.
>>>>>
>>>>> Lots of things to try, little time to go up on the mountain this week
>>>>> =] Gotta get part of the house ready for my sister whose family needs
>>>>> a place to stay for a couple of months as they relocate. Life is
>>>>> always interfering with my repeater work... *sigh* ;-)
>>>>>
>>>>> I appreciate your thoughts and feedback; I'll keep testing and trying
>>>>> things.
>>>>>
>>>>> Richard
>>>>>
>>>>>> On Mon, Oct 2, 2017 at 5:32 AM, David McGough <kb4fxc at inttek.net> wrote:
>>>>>>
>>>>>> Hi Richard,
>>>>>>
>>>>>> If your situation is that the repeater is just randomly generating an
>>>>>> active COS signal when its transmitter is un-keyed, this is most likely
>>>>> an
>>>>>> RF intermod or other interference problem. If you're at a site with
>>>>>> broadcast transmitters, something intermittently arcing (diode noise) is
>>>>> a
>>>>>> likely suspect. Look for (and remove/replace!) any loose, rusted/corroded
>>>>>> hardware near your RX antenna.
>>>>>>
>>>>>> If the repeater is getting back into itself so that you hear an audio
>>>>>> echo, this is most likely severe desense from the repeater's own
>>>>>> transmitter. Is the problem reduced/eliminated if you turn the
>>>>> transmitter
>>>>>> power down (temporarily)??
>>>>>>
>>>>>> Some antennas and types of feedline are more susceptible to PIM (passive
>>>>>> intermod) generation than others. For example, in general, it's best to
>>>>>> stay away from LMR style coax---any style that has a tinned braid over
>>>>>> aluminum foil (dissimilar metals). While LMR coax may work fine when
>>>>>> initially installed, after a few years, once a little corrosion has
>>>>>> started between the braid and foil, it starts causing noise problems.
>>>>> Some
>>>>>> style of heliax is preferred.
>>>>>>
>>>>>> ....Your antenna system needs to be virtually "perfect," of course, if
>>>>>> you're using a duplexer, or your TX will probably interfere with the RX.
>>>>>>
>>>>>> Without knowing more about your RF setup, it's hard to do more in depth
>>>>>> diagnostics??
>>>>>>
>>>>>>
>>>>>> 73, David KB4FXC
>>>>>>
>>>>>>
>>>>>>> On Sun, 1 Oct 2017, Richard Bateman wrote:
>>>>>>>
>>>>>>> Yeah, I'm using the URIx.  I'm having a couple of issues, but the one
>>>>>>> I'm trying to deal with right now is basically that there is some kind
>>>>>>> of noise that keeps keying up the repeater and we can't figure out
>>>>>>> where it is coming from. It might well just be that it's RF noise and
>>>>>>> we need to track it down, since I hear it when the repeater's squelch
>>>>>>> opens and there is no signal to listen to, but on the spectrum
>>>>>>> analyzer it's not strong enough to come out of the noise.
>>>>>>>
>>>>>>> Sometimes it'll sit there kerchunking over and over again, multiple
>>>>>>> times per second, despite the PL tone on the receive, and other times
>>>>>>> it's quiet as you could ask for. Putting an extra ground wire as you
>>>>>>> suggest sounds like it'd be worth a try to me =]
>>>>>>>
>>>>>>> One reason I've been considering trying dsp-based is to find out for
>>>>>>> sure if the issue is in the RF signal or if it's in the CTCSS/COR
>>>>>>> signalling when they shouldn't (for whatever reason, whether the
>>>>>>> radio, which is a TKR-750 version 1, or some electrical issue like a
>>>>>>> ground loop).
>>>>>>>
>>>>>>> Richard
>>>>>>>
>>>>>>> On Sun, Oct 1, 2017 at 7:44 PM, David McGough <kb4fxc at inttek.net>
>>>>> wrote:
>>>>>>>>
>>>>>>>> Hi Richard,
>>>>>>>>
>>>>>>>> Are you using a URI or URIx audio adapter?  If so, I've had superior
>>>>>>>> results by adding an extra, heavy-gauge ground lead to the URI. Then,
>>>>> I
>>>>>>>> directly connect this lead to the repeater chassis--a screw on a
>>>>> Kenwood
>>>>>>>> TKR repeaters...This has been my #1 ground-loop solution.
>>>>>>>>
>>>>>>>> Here are a few sample photos:
>>>>>>>>
>>>>>>>> https://hamvoip.org/kenwood-TKR/P1030817.JPG
>>>>>>>> https://hamvoip.org/kenwood-TKR/P1030820.JPG
>>>>>>>>
>>>>>>>> Test TKR-750-2 repeater on bench:
>>>>>>>> https://hamvoip.org/kenwood-TKR/P1030831.JPG
>>>>>>>>
>>>>>>>> ALSO -- on the TKR750/850 repeaters, make sure to notice that the
>>>>> 25-pin
>>>>>>>> accessory plug has separate analog and digital grounds!
>>>>>>>>
>>>>>>>> If you've got RF or other noise issues with simpleusb telemetry, I
>>>>> doubt
>>>>>>>> switching to usbradio DSP-based signaling will fix anything. Try
>>>>> running
>>>>>>>> the TX into a dummy load and test, if possible.
>>>>>>>>
>>>>>>>> 73, David KB4FXC
>>>>>>>>
>>>>>>>>
>>>>>>>>> On Sun, 1 Oct 2017, "Richard Bateman via arm-allstar" wrote:
>>>>>>>>>
>>>>>>>>> Hi,
>>>>>>>>>
>>>>>>>>> I've been having some issues that I'm starting to suspect might be
>>>>>>>>> related to RF getting into my interface cables triggering my COR and
>>>>>>>>> CTCSS lines (not in any way convinced, but it's on my list of
>>>>>>>>> suspects) and have been toying with the idea of using usbradio
>>>>> instead
>>>>>>>>> of simpleusb for awhile; last time I did that the audio was kinda
>>>>>>>>> crappy, so I switched to simpleusb.
>>>>>>>>>
>>>>>>>>> While looking around I noticed that there is a "TODO" on the hamvoip
>>>>>>>>> page about merging the channel drivers, which I assume might be
>>>>>>>>> something along the lines of using DSP for COR and CTCSS detect but
>>>>>>>>> using the other audio for actual TX?
>>>>>>>>>
>>>>>>>>> Anyway, I'm just wondering what the status of that is and if there is
>>>>>>>>> any way I can help with the efforts; it would help me out a lot on
>>>>>>>>> several different projects.
>>>>>>>>>
>>>>>>>>> Richard
>>>>>>>>> _______________________________________________
>>>>>>>>>
>>>>>>>>> arm-allstar mailing list
>>>>>>>>> arm-allstar at hamvoip.org
>>>>>>>>> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>>>>>>>>>
>>>>>>>>> Visit the BBB and RPi2/3 web page - http://hamvoip.org
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>> _______________________________________________
>>>>>
>>>>> arm-allstar mailing list
>>>>> arm-allstar at hamvoip.org
>>>>> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>>>>>
>>>>> Visit the BBB and RPi2/3 web page - http://hamvoip.org
>>>>>
>>>> _______________________________________________
>>>>
>>>> arm-allstar mailing list
>>>> arm-allstar at hamvoip.org
>>>> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>>>>
>>>> Visit the BBB and RPi2/3 web page - http://hamvoip.org
>>>
>>>
>>> .
>>> _______________________________________________
>>>
>>> arm-allstar mailing list
>>> arm-allstar at hamvoip.org
>>> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>>>
>>> Visit the BBB and RPi2/3 web page - http://hamvoip.org
>
>
> .